Buzzing on GSM audio

"Timo Jyrinki" <timo.jyrinki at gmail.com> writes:
>> My paranoid / not-knowing-what-I-do procedure is to:
> 1. change /usr/share/openmoko/scenarios/gsmhandset.state
> 2. alsactl -f /usr/share/openmoko/scenarios/gsmhandset.state restore
> 3. alsactl -f /etc/asound.state store
> 4. reboot
>
I've found using alsamixer helpful for testing and then comparing which
values changed against the original gsmhandset.state file. My procedure
usually goes something like this:
1. ssh to FreeRunner
2. Make a phone call
3. While call is in progress run alsamixer
4. Tweak settings to minimize buzzing/echo
5. While call is still in progress run:
$ alsactl store -f gsmhandset-test1.txt
Now you can diff this new file against the original
(/usr/share/openmoko/scenarios/gsmhandset.state) and see which settings
were changed. To make your changes persist for future calls just copy new
file (gmshandset-test1.txt) to
/usr/share/openmoko/scenarios/gsmhandset.state. To the best of my
knowledge you don't need a reboot.
--Andrew